curl --request GET \
  --url https://api.cartesia.ai/agents/documents/{document_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Cartesia-Version: <cartesia-version>'

{
  "id": "<string>",
  "name": "<string>",
  "content": "<string>",
  "created_at": "2023-11-07T05:31:56Z",
  "metadata": {}
}